Method for forming transformer structures



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- R v. ENGAY I METHOD FOR FORMIRG, TRANSFORMER STRUCTURES Filad Biarcn11. 1922 2 Sheets-Sheet 1 usy:

Nmn 6, 1923.

v. Ema/Av METHOD FOR FORMING TRANSFORMER STRUCTURES Filed Marqh 11, 19222 Sheets-Sheet 2 I N VEN TOR TTORNEY)" V. BIEFZGAY, OF EIT'ZCSBUKEG-H,EENEZSYLVAEHA, ASSIG-NOB 1 30 TRANSFOEMEB COEZQEPANY, A. CORZGEA'Z'IOEIF FENNSYLVANI&

EEETEQD "33GB FQBlflING TEAlJSFGEIG/IER STRUCTURES.

original application filed June 2, 1920, Serial No. 886,115. Dividedthis application filed lierch 11, .1922. Serial No. scale-o.

To all from it may 00 ricer-n Be it known that 1', ROBERT V. BIXGAL acitizen of the United Stat s. residing at, Pittsburgh. in the county ofAllegheny anal State 0? Pennsylvania, have invented certain net anduseful improvements in -Qilcthods for Forming Transformer Structures, ofwhich the following a specification.

This application is division of my application Serial Number 386.115.filed June 2, 1920. The. invention relates to method oi making tanks ofsheet steel for containing electrical transi iers or other devices.

The invention will he described with re ference to the accompanyingdrawings in Which- Fig. 1 illustrates the tank in vertical sectionslii-9W.

Figs. 2 to 1'2 inclusive illustrate successive steps in the formation ofthe tank, and

Fig. 13 illustrates the tank.

The tank K is preferably of sheet metal and preferably circular oral orrounded in section and the sides 22 are corrugated to a depth dependent,upon the size oi the tank and the relative cooling surface required.Hitherto the depth of these side corrugations has been limited bystrength and the diliiculty and expense of producing deep corrugations.'lhe shallower corrugations give a correspondinglv restricted coolingsurface and often it"ues been necessary to resort to extra cooling pipesor circulating means where the available air cooling of the tank itselfwould he. suflicient if properly provided for. in the tank oi thisinvention corrugations of the tank body may he of uny desired depth andstrength required by practice and at the some time these corrugationsare formed from sheet, metal plates in simple and inexpensive manner andthe resultant structure is strong and self-sustaining and. whenassembled with the hop and bottom port ions provides a rigid, durablecontainer.

building up the tank sides or body 22 a. rectangular sheet 23 (Fig. 2)is chosen "or out from the stantlarl sheet steel sizes in --nd the topand hottom edges oil the =.re notched as at, Q leaving; straight .ls 25between the notches, and in the specific example shown leaving haltintervals. 25 at each end. The notched sheet 23 is then bent, into aseries of parallel corrugaconsiderations 9 thereon by outer hoops lions(Figs. 3 and 4) and preferably the bends are made by a pivoted bender 26swinging around a former 27 and pressing or Wrapping the sheet aroundthe former. This method of bending the corrugations in succession givesa predetermined identical diameter to each bend and avoids anyoverstressing of the metal and any irregular or war ed etl ects. Thebends 28, 29 at the ends of tie corrugations are separated byintermediate substantially flat portions 30 and the inner bends 28 aremade between the notches 24 while. the outer bends :29 are cen- -teredat the peaks Ill of the notches the ends of corrugated sections having,the form shown 3 and} with the edges of bends 28 at right angles to thesheet and the edges of bends 29 inclined. The corners 3:2 or" thenotches form a line near the inner bends .28.

The next step in the, formation of the tank body is illustrated in Figs.5 and (5 and comprises bending the corrugated section as a Whole into acircular arc corresponding in diameter to the diameter oi the tank beingbuilt. This is accomplished by pressing the inner bends 28 toward eachother to slightly narrow the spaces between them and correspondinglyspreading apart the outer bends to increase their splicing. a templatebeing used to gage the spacing of the bends. Then a number of sectionshave been formed and curved as shown in Figs. and 6 these sections areassembl d side by side in scniicir cular cradles 33 corresponding tovtheouter diameter of the tank and the assembled sections are weldedtogether along their meeting edges which are on the inside of the tank,and in this way a circular section is onilt up in the form for instanceof a semicircle snd corresnondino to half of the tank body. The. otherhulf of the tank body is similarly built, up and the two halves areassembled together on circular needs or leinplates 35 {Fig 10)corresponding to the inner diameter of the tank and are hound The twosections are then welded together along their meeting edges at theinside of the 'llictank body so formed its corrugations open at the topand bottom and the nextv step in process is the closing of thesecorrugations in such manner as to iorm a rigid arched structure in whichthe corrugations mutually support each other .V is flattening turning noinner corrugations 28 incl" The. end edges of these "dg'ilolOfiS isalsttenetl out into sub s obiolly strai lines as indicated a t-38 s... ecorrugations are spread ll? 3 i toward and finally into as indicated at;40

"llZLlPlQ pot-- a o hamcontact; along together along of "he i- :19 o C2axon s ing outward .lI L U'OIlS 28 forms t e corners 32 oi the notch escontinuous annular ridge the tank from which the in opposite directions.

i ormgstion is arched A. i seam, and all corrugations converge to t s2CQII nations are I bu reinforce sustain o other through 1 connection.All through this structure show a (-hsuc- 'itinuons corrugations with sbends, 1th a tank consortiu to the met'notl. of thi some one; sixteenHQFESSBYY U) ts in stoc;

l may be in to e tank and foe'for ea may be I it with ho shops which intho finally bent The of corrngmion bends around a he metal and does not,draw J1EE it or leave it with interhe final closing of the corrusectiesshouncl together and lvmoed against warping by the Inner heads 35 anolthe outer ho ds no two encls of the tank body are l identical findsonosled c} h the corrugations inclined 1nd siolieel end and rigiclly lvertical sec n m r Y x 1 s is iClAeL on (and on nonzonml sot.

"welding is (lone with the tank 7 a continuous annular end portion ateach and. This tank hotly is very strong irrespectivoof its connectionwith the bottom and cover pieces. At each encl it provides an annularhowled surface formed by the ring: ot lfll'lliutl fluttvnotl surfaces 39and this beveled surface serves for the attach: ment of tho bottom andtop pieces in a simple and vol-y rigid manner.- "When the bot lom andtop pieces are in place, as herein alter (loscriluul, this strongtubular portion ,YGlHi OTUS the end portions in such manner that eachpart is l'i'ussctl against the other to m ive the strains put upon thetank.

The bottom Ill of the tank is formed by a circular plute. preferably ofrolled steel, with its edge flanged upwardly at on anglo (Fig. 11) andthis edge flange s tlzs bottom is nearly at right angles to the beveledsurfaces 39 and is just fitted to an intermediate portion of thesesurfaces. With the bottom piece M assembled and clamped in place a heavyWllll 46 is Made in the cornei' between the surfaces 39 and the flange515 so that the hottom surface of the tank is liclow the surface of thisWeld which will tlie -et'ow he held spaced from the base B of thetransformer in linsll assembled position. This ilzmging of the bottomplate ll l' gives this plate on arched construction and protects itagainst Warping due to tho host of the wchling opsration and sine to anystrains on it, in service; and this arching at the bottom also holds theWelded seam away from conta t with the hose or other surfaces so thatthis seam (loos notv collect n'ioistni'e nnrl hccomo rusty or weaken orWear in use. This c ms fruction permits the bottom plate and the topring, or either, to be made eithor thicker or thinner than the metal inthe tank body, or of the same thickness as may he most s lvantaqeous.

The top of the tank body has weltlecl to it the steel or iron angle ring.50 formed by rolling am angle into circular toz'm with its flangeSl'inclined :itv substantially the an gle of lhe tank cover (I and theends of the circle welded together. This ring; 50 is sizerl to tit intothe top of the tank and engage an intermediate portion of the beveledSUTTGCBS 39 at the top and is fastened in place liy lwavy Welding 52 allaround in the annular corner between the surfaces 39 and ring 50. ThisIlflg' formsa-(lrlitional reinforcement oi the tank hotly and provides astrong and simple connection for the tank cover (1.

In the combination of this invention the methorl of forming the tank andthe tank hotly in its trussed or arc-lied structure per- Knit the usepfthe sheet steel stock and this hotly is furthermore not required tosustain the weight of the transformer parts. The corrugations of thetank body may be mscls oisny depth to give the cooling surfsos required.ihese corrugations overhang at the sides and are formed with wellrounded bends 29 to give a large passage for the circulation or, the oilalong the most exposed surfaces and in their entire area provide anextended cross section acting like large pipes for the circulation ofthe oil. This system efi'ect noalnas pipes or conduits P of thecorrugations which have a great proportion of their surface exposed tothe air and "separate the inner heated currents of. oil from the outercooled currents and an inner battle cylinder or guide vanes may heprovided just Within the bends The columns of cooled oil in thecorrugations are relatively heavy and pass down rapidly through thecorrugations drawing in heated currents of oil at the top 61 and at thebottom 62 replacing the oil rising through the transformer coils.

By the method of this invention the relative area of the outer coolingdates and the inner passages through and around the coils and core maybe made in most effective proportion and this circulatory systemprovides definite areas of heating and cooling, avoids interferenebetween the rising and descending currents, and in effect gives a forcedcirculation which by the outer rapid passing of the oil down throughthe-corrugations distributes the heated oil over a larger area of thetransformer sides and instead of accumulating as hereto-lore within arelatively small area the top with slow and sluggish progress down thesides the oil is rapidly circulated downward through the pipes formed bythe corrugations. The temperature gradient at the sides therefore ismuch less abrupt and the cooling taking place over a much larger area ismuch more eiiicient.

The tank of this invention also provides unobstructed paths for thecooling air rising around the sides and in between the cormnutions.These corrugations overhang even at their lower ends so that the coolingcurrents of air have access at the very bottom. They also meet with Warmsurfaces at a relatively short distance from the bottom and theirabsorption of heat is distributed (HT-l a large proportion of their ofpath. All of these conditions make for a thorough and efiicicnt transferof heat from the oil within the tan-k to the air outside so that thetank of this invention will efficiently cool a transformer underconditions whore it has heretofore. been necessary to use extraradiators or cooling coils or pump circulation.

The method and structure of this invention therei'orc combine aninexpensive procof i anufacture with etficiency and durability inservice. This invention is adaptahis not only to standard lines andtypes of transformers to be made up in quantity be readiiy varied tonewt the number of sections 23 in a given transformer body is a matteror the most economical use of the steel; in hand after the desired depthor" the corrugations and the total area of the body is determined. Withtransformers of excessively large size or where great strength isrequired an increase in the gage of metal in the body may make iteconomical to make only a single corrugation each section 23. in suchcase the bend of this corrugation is directed outward and the innermeeting edges of adjacent sections are also flanged over and turnedoutward and welded togetheralong the inside between these flanges asindicated at (36 (Figs. 5 and While this invention has been illustratedin connection with a specific embodiment of transformer and tank it isnot confined thereto but is intended to cover such modifications thereofas fall within the scope of the appended claims it will also heunderstood that the parts may, desired, he brazed instead or welded.

I claim l. The method of forming a tank body from a plurality of sheetscomprising notching' said sheets, corrugating and bending said sheetsinto desired shape to form the tank body with inner out-er channelsbetween the corrugations and bending}; the. ends of the inner channelsoutward and closing the ends of the outer channels by hendingthem overin arched form and welding along the meeting edges, said corrugatedsheets being loll fastened together by Welding to form the tank body.

2. The method offorrninga tank body from a plurality of steel sheetscomprising corrugating and bending said sheets into desired shape toform the tank body, bending outward the inner portions of the ends ofthe corrugations to bring them together in the form of a ridge at theend of the tank, and closing the ends of the corrugations by welding,said corrugated sheets being fastened together by welding to form thetank body.

3. The method of forming a tank body comprising welding togethercorrugated steel sheets to form a tubular portion, bendin; over the endsof said corrugations so that they rneet in arched form edge to edge,closing the ends of said corrugations-by welding, and welding endportions to the ends of said tuhulur portion at the inner circumferencethereof. o

4. The method of forming a tank body comprising Welding togethercorrugated steel sheets. bending the ends of the inner corrugations intoa continuous circular edge. closing the ends of the corrugations byWelding, and Welding the edges of an end i and continuous circular edge.u, 'i he method of forming a tnllli which consists in cutting series oirectangular h iiola has an and cut with a nil straight portions, forming11 v of parallel hen ls coinciding: n the apcxes oi" said notches and:nnldlc of iid six-night portions, assciniiliiig said sheets hl'usicningg the edges of anliace I sheets; together to form a tubularstruck me.

bending luu'li the inner oi the i-orz-iunnions to {win an in ()ill'nlliYCiIIi'il NCililzli surface, closing the open emle; of thecorrugations. lilting 1 end portion against the inclined rci'niul SMITH/itil l nelzlingg u filler n he-uncle between rlinwl p rtion.

liml of forming a tank of sheet the steps of cori'ngating b no sheetmetal to form a tank of curved (:1058 section with inner'and outerhannels hendin; he ends of the inher {'lkr ill u. an inclination, anddosing; over ends of the outer anncls a ndingr and welding alongsni'laces in s 1 that both the inner and Miss the fluid currents rod offorming a tank of sheet the steps oi commenting a slicemetal lo form ittank ;ion with inn'c and ilie ends of the inoutward at an inclination,over the en z-i of the outer channels face i. ciinn'ig inwardly bybring- Llm: and weicling so that and outer channels freely uppe r passthe fluid currents at their ends and welding circular members to theoutwardly inclining ends of said inner channels at each end of the tank.

A method of forming a. tankl body of sheet metal'colnprising the stepsof corrugating said sheet metal with successive rouinled bends in thesheet metal and relatively lint portions interveningbetween saidbends-to provide outer and inner channels, bending said corrugated sheetmetal into the curved form of the tank body by spreading the outer bendsto space than farther apart and correspondingly widening the outerchannels and'closing over the ends of the inner channels of saidcorrugations by bending and Welding along surfaces inclining inwardly sothat both the inner and outer channels freely pass the fluid currents attheir ends.

9. A method of forming a tank body 0;

sheet metal comprising the steps of corrugatinq said sheet metal withsuccessive rounded bends in the sheet metal and relatively flat portionsintervening between said bends to provide outer and inner channels,bending said corrugated sheet metal into til; curved form of the tankbody by reading the outer bends to space them fart er apart andcorrespondingly widening the outer channels, and closing over the endsof the inner channels of said corrugations by bendingnnd welding alongsurfaces inclining inwardly so that both the inner and outer channelsfreely pass the fluid currents at their ends, the opposite fiat sides ofeach inner channel being nearly parallel to each other.

ROBERT V. BINGAY.

